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HomeMy WebLinkAboutItem 7B, Inflow and Infiltration Update ~ ~HILLS Request for Council Action . Prepared By: Kristine Giga Council Meeting Date: May 12, 2008 Inflow and Infiltration Update Budgeted Amount: $100,100 Actual Amount: $7,200 Funding Source: Sanitary Sewer FundNarious Recommendation: Authorize staff to hire an additional seasonal part-time employee for 2008 for an amount not to exceed $7,200. Supporting Documents: 1. Memorandum dated May 7,2008 from Public Works Director Greg Hoag and Civil Engineer Kristine Giga Chuck Janski of Bonestroo will be present for the discussion. MEMORANDUM DATE: May 7, 2008 TO: Mayor and City Council Jim Willis, Interim City Administrator FROM: Greg Hoag, Public Works Director Kristine Giga, Civil Engineer SUBJECT: Inflow and Infiltration (1&1) update BACKGROUND On March 31, 2008, staff presented the City Council with the Inflow and Infiltration (1&1) report prepared by Bonestroo, which discussed initial results of the study and recommended next steps. Staff presented a work plan and requested approval of additional study on April 14, 2008. The City Council requested additional information for the 2008 work plan; at this time, staff is providing an update. DISCUSSION Additional studv in prOl!ress: Lift station calibration Public Works staff is in the process of calibrating the fourteen lift stations (establishing pump cycle times) so that the daily flow data retrieved can be better evaluated. This process takes about 1.5 hours per lift station; we expect to complete this in the next two weeks. Pump station monitors have been installed at Lift Stations 11 and 13 to further break down the metershed to MCES meter 059 ( on West Round Lake Road). Temporarv flow meters Two flow meters will be installed Wednesday, May 14. We anticipate the meters will be in place for four to six weeks, depending on the weather. The meters need to monitor "normal C:\Documents and Settings~ackie.freppert\Local Settings\Temporary Internet Files\OLKDl \5-12-08Memoll.doc 1&1 5/8/2008 Page 2 flow" and "high flow". High flow occurs when we receive significant rain events. However, if we have a drier than normal period, the length of time the meters are in place may need to be extended. Smoke testing Smoke testing is recommended to occur in the summer, after the streets are swept and catch basins are cleared of leaves and debris. This allows the smoke to be more visible to those completing the testing. Staff is working with Bonestroo to coordinate this work for June. At this time, the consultant recommends the following areas be included in smoke testing: the area flowing to the Glenarden neighborhood (proposed 2009 PMP), and the area flowing to Lift Station #11 (northwest corner ofthe City.) Sanitary Sewer televising The process to televise sanitary sewer lines is two-fold. One two-person crew is needed to clean and jet the lines prior to televising, and another two-person crew follows with the televising equipment. Last summer each of these crews consisted of one full time employee and one seasonal employee. The cleaning crew periodically needs an additional crew operating the vactor truck to suck excessive debris from the manholes. Staff estimates that we are cleaning approximately 450 feet per hour, and televising 500 to 600 feet per hour. Areas to be televised: In 2008, staff is focusing on televising sewer lines in low and/or wet areas, especially near ditch systems and lakes. 23,500 feet (4.5 miles) of televising is planned around Round Lake, Lake Johanna, along Highway 10, and in the Valentine Avenue neighborhood (between Lake Valentine Road and 694). Staff estimates that it will take about 52 hours to clean and 47 hours to televise these lines, which is scheduled for completion by the in early June. Once these areas have been televised, staff will continue to work on other areas ofthe City left to be televised. In 2007, approximately 61,000 feet (11.5 miles) were televised. Through 2007, approximately 65% (27 of 42 miles) of the City has been televised. Staffs goal is to televise approximately 30,000 feet (5.7 miles) in 2008. Manhole inspection Manhole inspection also involves a two-person crew; for safety reasons, a two-person crew is required if manhole entry is required for detailed inspection. It takes approximately 20 minutes to complete a manhole inspection (or 0.65 total man hours). We have identified three areas in the City for manhole inspections in 2008; 147 manholes are located in these areas. Staff estimates approximately 50 hours for a two-person crew to complete the identified inspections. Once televising is cornpleted, the crew will switch gears to manhole inspection; this work will be completed in mid June. As we gather additional information from other analysis such as flow meters, staff will identify additional areas where manhole inspections should be completed. 1&1 5/8/2008 Page 3 Staff time involved The Public Works Department crew consists of eight full time maintenance employees who are cross trained to work in all areas of the department to include: Sanitary and Storm Sewer, Water, Parks, Streets, and General Facility and Building Maintenance. Work load is generally spread into the following categories: Sanitary/Storm 2.5 FTE Water 1 FTE Parks 2.5 FTE Equipment/repair/misc. 1 FTE Streets 1 FTE Traditionally, we have hired six (6) seasonal part-time workers; they are distributed as follows: Sanitary/Storm 1 Water/Street 1 Parks 4 In order to accelerate the 1&1 study, staff would like authorization to hire a seventh part-time employee for the summer. This additional employee would assist with the televising crew, or be the second person on the manhole inspection crew. It is anticipated that the cost to add an additional seasonal employee for 15 weeks will not exceed $7,200.00. Proposed improvement proiect timelines: Sanitary sewer lining proiects: This will be a joint project with Roseville. Both Cities are currently reviewing their records and videos, identifying candidates for this project, and will coordinate to have areas determined by early June, so the project can be advertised and a contract awarded in July. Manhole rehabilitation proiect: Manhole inspections have been completed for approximately one-third ofthe City, or the area that flows to Met Council meter 059 (Round Lake). Ofthe approximately 300 manholes, some level of repair is needed to about 100. Needed repairs vary from replacing casting rings and installing a chimney seal to regrouting manholes and repairing structural cracks or leaks. In an effort to allow our staff to focus on identifying the source ofI&I, we propose to assemble a manhole rehabilitation project that incorporates all levels of repair. Staff anticipates that this project would be ready to advertise in July; this project will be brought back to council to award the contract. Sump Pump Inspection Program: City Staff has received printed information and had follow up conversations with the Cities of Mounds View, New Brighton, and Little Canada regarding their sump pump programs. All three of these Cities' programs are different; staff from each City has provided us with excellent feedback on what worked well and what did not work well. Our first 1&1 5/8/2008 Page 4 step in our process is to compile a spreadsheet of the results from the 2000 inspection program to determine ifthere is an area in the city that should be focused on sooner rather than later, and to determine how much of a potential issue sump pumps may actually be. Administrative support .staffwill be compiling this data over the next few weeks. After this data is analyzed, we will develop a recommended inspection program and present it to the City Council. It is our goal to have a recommendation by the end of June. FINANCIAL IMPLICATIONS It is anticipated that an additional seasonal employee, hired for 15 weeks at 40 hours per week at $10.00-$12.00 per hour, would cost $7,200.00. Staff will bring proposed manhole repair, sanitary sewer lining or other identified improvement projects to the City Council for authorization at a future meeting; estimates for these projects are unknown at this time. RECOMMENDED COUNCIL ACTION Authorize staff to hire an additional seasonal part-time employee for 2008.